Move and rename RenderBR to LayoutBR.

LayoutTests/platform/mac/fast/block/float/021-expected.txt

Index: LayoutTests/platform/mac/fast/block/float/021-expected.txt
diff --git a/LayoutTests/platform/mac/fast/block/float/021-expected.txt b/LayoutTests/platform/mac/fast/block/float/021-expected.txt
index b8c02eede3c905d0d0576182d7c35e4e4f8dde41..78d2339cb0e6d9518ad04b5a17812bb0a90b67db 100644
--- a/LayoutTests/platform/mac/fast/block/float/021-expected.txt
+++ b/LayoutTests/platform/mac/fast/block/float/021-expected.txt
@@ -10,7 +10,7 @@ layer at (0,0) size 785x3166 backgroundClip at (0,0) size 785x585 clip at (0,0)
       RenderBlock {DIV} at (0,52) size 720x240 [border: (10px solid #000000)]
         RenderText {#text} at (10,10) size 313x18
           text run at (10,10) width 313: "You should see blue and green rectangles below."
-        RenderBR {BR} at (322,24) size 1x0
+        LayoutBR {BR} at (322,24) size 1x0
         RenderBlock (floating) {DIV} at (10,28) size 1500x100 [bgcolor=#0000FF]
         RenderText {#text} at (0,0) size 0x0
         RenderBlock (floating) {DIV} at (10,128) size 1500x100 [bgcolor=#008000]
@@ -26,7 +26,7 @@ layer at (0,0) size 785x3166 backgroundClip at (0,0) size 785x585 clip at (0,0)
       RenderBlock {DIV} at (0,564) size 720x240 [border: (10px solid #000000)]
         RenderBlock (floating) {DIV} at (10,10) size 1500x100 [bgcolor=#0000FF]
         RenderBlock (floating) {DIV} at (10,110) size 1500x100 [bgcolor=#008000]
-        RenderBR {BR} at (1510,10) size 0x18
+        LayoutBR {BR} at (1510,10) size 0x18
         RenderText {#text} at (10,210) size 312x18
           text run at (10,210) width 312: "You should see blue and green rectangles above."
       RenderBlock {DIV} at (0,820) size 720x240 [border: (10px solid #000000)]
@@ -44,7 +44,7 @@ layer at (0,0) size 785x3166 backgroundClip at (0,0) size 785x585 clip at (0,0)
         RenderBlock (floating) {DIV} at (10,10) size 1500x100 [bgcolor=#0000FF]
         RenderText {#text} at (10,110) size 287x18
           text run at (10,110) width 287: "You should see blue above and green below."
-        RenderBR {BR} at (296,124) size 1x0
+        LayoutBR {BR} at (296,124) size 1x0
         RenderBlock (floating) {DIV} at (10,128) size 1500x100 [bgcolor=#008000]
         RenderText {#text} at (0,0) size 0x0
       RenderBlock (anonymous) at (0,1588) size 769x18
@@ -53,7 +53,7 @@ layer at (0,0) size 785x3166 backgroundClip at (0,0) size 785x585 clip at (0,0)
       RenderBlock {DIV} at (0,1622) size 720x240 [border: (10px solid #000000)]
         RenderText {#text} at (10,10) size 313x18
           text run at (10,10) width 313: "You should see blue and green rectangles below."
-        RenderBR {BR} at (322,24) size 1x0
+        LayoutBR {BR} at (322,24) size 1x0
         RenderBlock (floating) {DIV} at (10,28) size 698x100 [bgcolor=#0000FF]
         RenderText {#text} at (0,0) size 0x0
         RenderBlock (floating) {DIV} at (10,128) size 698x100 [bgcolor=#008000]
@@ -68,7 +68,7 @@ layer at (0,0) size 785x3166 backgroundClip at (0,0) size 785x585 clip at (0,0)
       RenderBlock {DIV} at (0,2134) size 720x240 [border: (10px solid #000000)]
         RenderBlock (floating) {DIV} at (10,10) size 698x100 [bgcolor=#0000FF]
         RenderBlock (floating) {DIV} at (10,110) size 698x100 [bgcolor=#008000]
-        RenderBR {BR} at (708,10) size 0x18
+        LayoutBR {BR} at (708,10) size 0x18
         RenderText {#text} at (10,210) size 312x18
           text run at (10,210) width 312: "You should see blue and green rectangles above."
       RenderBlock {DIV} at (0,2390) size 720x240 [border: (10px solid #000000)]
@@ -86,6 +86,6 @@ layer at (0,0) size 785x3166 backgroundClip at (0,0) size 785x585 clip at (0,0)
         RenderBlock (floating) {DIV} at (10,10) size 698x100 [bgcolor=#0000FF]
         RenderText {#text} at (10,110) size 287x18
           text run at (10,110) width 287: "You should see blue above and green below."
-        RenderBR {BR} at (296,124) size 1x0
+        LayoutBR {BR} at (296,124) size 1x0
         RenderBlock (floating) {DIV} at (10,128) size 698x100 [bgcolor=#008000]
         RenderText {#text} at (0,0) size 0x0